Production of hydrocarbon products



Nov. 7, i933. M. PIER ET Al. 1,934,001

PRODUTON OF HYDROCRBON PRODUCTS Filed Aug. 28, 1928 Patented Nov. 7,- 1933 UNITED STATES PATENT OFFICE PRODUCTION OF HYDROCARBON PRODUCTS pany, Linden, N. J., ware Application August 28,`

and in Germany 7 Claims.

This invention is an improvement in the invention forming the subject matter of application for patent Ser. No. 86,646, led February 6, 1926, and relates to the production of valuable hydrocarbons and derivatives thereof, hereinafter referred to for the sake of brevity as hydrocarbon products, by destructive hydrogenation of liquid carbonaceous materials such as substances of the nature of coal made into suspensions or pastes, tars, mineral oils and the like, their constituents and conversion products.

Attempts have already been made in the cracking of hydrocarbons, such as mineral oils, tars and the like and in the low temperature carbonization of substances of the nature of coal, to prevent the formation of gas and at the same time to obtain the highest possible yield of valuable products, especially those of low boiling point, by suddenly lowering the previously existing pressure on the products at the close of the reaction, as for example to atmospheric or below atmospheric pressure, by the aid of a vacuum. This process however has the drawback that, under certain conditions, the deposition of coke and the formation of gas are not sufliciently prevented, and the initial materials are not completely converted into valuable products, such as benzines, lamp oils, lubricating oils and the like.

We have now found that the aforesaid liquid carbonaceous materials are to a large extent converted into valuable liquid products, without any appreciable formation of gas and deposition of coke, if the initial materials be subjected to treatment by destructive hydrogenation with hydrogen, or gases containing or supplying the gen or a gas containing or supplying hydrogen' under high pressure and the resulting product at least in the nal stage in the-gaseous or vaporous phase to la treatment with hydrogen under a comparatively low pressure.

lIt has been found that working with only one -pressure stage is not always suitable for the object in view. 1f, for example, oils of high boiling point are treated, in liquid form, with hydrogen under a pressure of 1000 atmospheres, and at a corporation of Dela- 1928, Serial No. 302,640, September 1, 1927 an elevated temperature, the said high boiling initial materials are converted into products of lower boiling point of the character of the middle oils. When treated under a pressure of 200 atmospheres, the same initial materials furnish a larger proportion of products of the benzine type and less of those of the middle oil character. Again, treatment under a pressure of 20 atmospheres, for example, leads to substances of the benzine type, and to formation of carbonaceous residues and gas, scarcely any middle oils being produced. Hence, each pressure stage leads to a specific result and consequently, if the same pressure be employed throughout the process, the best possible results are not always obtained. 7. For example, no benzines are obtained in one case, whilst in another losses are sustained through the formation of gas, coke and the like.

According to the present invention; the process is carried out by first treating the initial materials in the liquid phase, under very high pressure, approximately 200 to 1000 atmospheres of the hydrogenating gas. In some cases it will be convenient to employ lower pressures in the rst stage for example pressures of about 100 atmos-y pheres, or even lower. According to this manner of working the said materials, such as high boiling oils, are completely converted into middle oils. These are condensed, for example in a stripper, which is alsounder high pressure, whilst the hydrogen is returned in circulation to the reaction chamber. The deposited oil is drawn off from the stripper and is then treated in a second system with circulating hydrogen in the gaseous phase, under a pressure of from about 20 to 50 atmospheres, whereby considerable heat is evolved and the middle oil is completely converted into benzines. Thus, the initial materials are completely converted into -low boiling products without any losses being sustained.

The combination of the decreasing pressure stages enables also other advantages to be obtained. Thus,.any special addition of hydrogen may be dispensed with in the final, or benzineproduction stage. If, for example, the rst stage 100 be conducted at 200 atmospheres pressure, and the pressure on the resulting product be reduced to from 20 to 30 atmospheres, a sufficient amount of initially dissolved hydrogen 'will be liberated from the said product to carry through the stage 105 of benzine production in the gaseous phase. In some cases the final stage may even be carried out under atmospheric pressure.

According to the selection of the initial material, the temperatures, the catalysts (if any) and 110 the pressures employed in thevarious stages, larger or smaller portions of benzine, lamp oil or lubricating oil will be obtained.

It is preferable to work with exclusion of such substances as are liable to lead to the formation of methane and the deposition of coke.

The process is usually carried out at temperatures ranging between about 300 and 700 C. When working in the vaporous phase, higher temperatures may be advantageously employed than when working in the liquid phase. Thus, for example, when working in the liquid phase it will in some case be advantageous to employ temperatures ranging between about 420 and 450 C. whilst in the same case, when carried out in the gas phase, temperatures of between 450 and 480 C. may be employed.

Suitable catalysts are for example such cori--v sisting of/or containing the metals from the 6th group of the periodic system or the compounds thereof. Compounds of sulfur may also be employed with advantage as constituents of the catalysts for the present process. Again compounds containing fixed nitrogen, such as ammonia or its compounds or the nitrids stable against the action of water yield particularly good results. f

The manner of carrying out the invention in practice will be further illustrated with reference to the accompanying drawing which shows an apparatus for carrying out the process in elevation and partly in vertical section.) It should be understood that the invention is not limited to operations carried out in the particular form of apparatus illustrated.

A liquid carbonaceous material, for example a crude mineral oil is introduced into the system together with hydrogen at A, under a, high pressure, for example of about 200 atmospheres by means of a pump not shown in the drawing and is passed through the heat exchanger B, where it takes up heat from the reaction products issuing from the `high pressure reaction vessel Ei which are passed in counter-current to the fresh feed. The fresh feed thus preheated passes out from the heat exchanger at C into the preheater D in which it is heated about to the temperature to be employed in the high pressure reaction vessel E. The carbonaceous initial materials issue from the preheater D in a liquid state are passed into the high pressure reaction vessel E which is filled with the catalyst F. They are destructively hydrogenated in the said vessel in the liquid phase. 'I'heproducts of the treatment in the vessel E are passed through the cooler G to the separator H. The liquid products deposited in the said separator are thereupon passed on to a second high pressure reaction vessel E1 through a pressure reducing Valve R. By means of said valve the pressure may be reduced, for example to about 20 atmospheres, whereby the liquid materials are simultaneously brought into the vaporous state. If required, a preheater V may be arranged between the reducing valve R and the point of introduction into the said vessel S. The reaction vessel E1 in which the destructive hydrogenation in the gaseous phase and under lower pressure is carried out is filled with the catalyst Fi. The reaction products issuing from the vessel E1 are passed through the heat exchanger B to the stripping vessel M1. The hydrogenating gases are withdrawn at U and may be recycled, if desired, if-necessary after purification. The liquid reaction products are drawn off at N1. The gases issuing from the separator H at J are Example American crude mineral oil, containing from 40 to 50 per cent of constituents boiling above 350 C., is treated in the liquid condition with hydrogen at 200 atmospheres pressure and at about 450 C. in the presence of a catalyst containing molybdenum and chromium. Without any previous separation, the product is expanded into a second reaction chamber in which a pressure of 20 atmospheres and a temperature of about 480 C. are maintained. Here the product, in the state of vapor, is exposed to the action of a catalyst containing molybdenum and chromium. The mixture of gas and Vapor issuing from the reaction chamber is cooled under pressure and deposits a mixture of hydrocarbons which mainly consists of a benzine possessing excellent properties, since it has little or no tendency in knocking, and is adapted for direct use in internal combustion engines. The constituents boilingiabove 200 C., that is about 25 to 30 per cent, of the products obtained, can be used as lamp oils. Only a small residual amount boils above 325 C. and there are no losses due to the formation of gas and coke.

When working with a constant pressure of 200 armospheres an inferior benzine is obtained, 115 and the proportion of the products boiling above 200 C. is larger.

In a similar manner, very heavy oils, especially those which contain asphaltum, may be converted, rst at 1000 atmospheres into heavy middle oils, without loss through the formation of gas and coke, say at about 420 to 430 C., and subsequently at 200 atmospheres, at about 430 to 450 C., and in a third stage at 20 atmospheres at about 450 to 480 C., in the gaseous phase into a benzine, the boiling point curve and the like of which correspond to the requirements of a `good fuel for internal combustion engines.

What we claim isz- 1. In the production of valuable hydrocarbon products bythe destructive hydrogenation of high boiling liquid bituminous materials, the step which comprises treating said materials by destructive hydrogenation with hydrogen at a temperature and pressure suitable for destructive hydrogenation, in several stages, at least the first stage being effected in a reaction zone in the liquid phase with a pressure of said gas ranging between and 1000 atmospheres and at a temperature slightly below the midpoint of the usual destructive hydrogenation range such that said bituminous materials are substantially entirely converted into 'oils of middle oil character, said oils being in the final stage expanded into a reaction zone and treated in that zone in the vapor phase at a higher temperature than in the first stage but not exceeding 60 C. higher and a pressure of between 20 and 50 atmospheres to thereby produce oils comprising benzines. 150

2 In the production of valuable hydrocarbon products by the destructive hydrogenation of high boiling liquid bituminous materials, the step which comprises treating the said initial materials by destructive hydrogenation at a temperature and pressure suitable for destructive hydrogenation with a hydrogenating gas consisting of a gas supplying hydrogen, in several stages, at least the rst stage being eiected in a reaction zone in the liquid phase with a pressure of said gas ranging between 100 and 1000 atmospheres and a temperature within the range usually employed for destructive hydrogenation such that said bituminous materials are substantially entirely converted into oils of middle oil character, said oils being in the final stage expanded into a reaction zone and treated in that zone in the vapor phase at a higher temperature than in the iirst stage but not exceeding 60 C. higher and a pressure of between 20 and 50 atmospheres to thereby produce oils comprising benzines.

3. A process as dened in claim 2 wherein at least one stage is effectedin the presence of a catalyst comprising a metal of groupv 6 of the periodic system.

4. In the production of valuable hydrocarbon products by the destructive hydrogenation of high boiling liquid bituminous materials, the step which comprises treating the said initial materials by destructive hydrogenation at a pressure suitable for destructive hydrogenation with hydrogen, in several'stages, at least the rst stage being effected in a reaction zone in the liquid phase with a high pressure of said gas and a temperature of between 420 and 450 C. to convert said bituminous materials substantially entirely into oils of middle oil character, said oils being in the nal stage expanded into a reaction zone and treated in that zone in the vapor phase at a temperature ranging from 450 to 480 C., and a lower pressure than in the rst stage to thereby produce oils comprising benzines.

5. A process as defined in claim 4 wherein the first stage is carried out at a pressure of the l hydrogen gas ranging fromy 100 to 1000 atmospheres and the second stage at a. pressure of between 20 and 50 atmospheres.

6. In the production of valuable hydrocarbon products by the destructive hydrogenation of high boiling liquid bituminous materials, the step which comprises treating the said initial materials by destructive hydrogenation with hydrogen, in seV- eral stages, at least the first stage being effected in a reaction zone in the liquid phase at al pressure of 100 to 1000 atmospheres of the hydrogen and a temperature ranging between 420 to 450 C. to thereby convert said bituminous materials substantially entirely into oils of middle oil character, said oils being in the nal stage expanded into a reaction zone and treated in that zone in the vapor phase at a temperature of between 450 and 480 C. and a pressure of between 20 and 50 atmospheres to thereby produce oils comprising benzines, at least one of the above stages being carried out in the presence of a catalyst comprising a metal of the sixth group of the periodic system.

7. In the production of valuable hydrocarbon products .by destructive hydrogenation of liquid bituminous materials, the step which comprises treating mineral oil by destructive hydrogenation with a hydrogenating gas consisting of hydrogen in several stages of diminishing pressure in such a manner that the initial material is destructively hydrogenated in the first stage in the liquid phase-under a pressure of about 200 atmospheres of hydrogen and at about 450 C. in the presence of a catalyst containing molybdenum and chromium to convert said bituminous materials substantially entirely into oils of middle oil character and the product thus obtained is destructively hydrogenated in a second stage in the vaporous phase under a pressure of about 20 atmospheres and at a temperature of about 480 C. in the presence of a catalyst containing molybdenum and chromium.

MATHIAS PIER. KURT WISSEL. 

